x86/efi: Rip out phys_efi_get_time()

Dan reported that phys_efi_get_time() is doing kmalloc(..., GFP_KERNEL)
under a spinlock which is very clearly a bug. Since phys_efi_get_time()
has no users let's just delete it instead of trying to fix it.

Note that since there are no users of phys_efi_get_time(), it is not
possible to actually trigger a GFP_KERNEL alloc under the spinlock.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 0 insertions, 29 deletions

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 43e7cf6c6111..3781dd39e8bd 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -246,21 +246,6 @@ static efi_status_t __init phys_efi_set_virtual_address_map(
         return status;
 }
 
-static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
-                                             efi_time_cap_t *tc)
-{
-        unsigned long flags;
-        efi_status_t status;
-
-        spin_lock_irqsave(&rtc_lock, flags);
-        efi_call_phys_prelog();
-        status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
-                                virt_to_phys(tc));
-        efi_call_phys_epilog();
-        spin_unlock_irqrestore(&rtc_lock, flags);
-        return status;
-}
-
 int efi_set_rtc_mmss(const struct timespec *now)
 {
         unsigned long nowtime = now->tv_sec;
@@ -592,16 +577,9 @@ static int __init efi_runtime_init32(void)
          * EFI runtime services before set_virtual_address_map
          * is invoked.
          */
-        efi_phys.get_time = (efi_get_time_t *)
-                        (unsigned long)runtime->get_time;
         efi_phys.set_virtual_address_map =
                         (efi_set_virtual_address_map_t *)
                         (unsigned long)runtime->set_virtual_address_map;
-        /*
-         * Make efi_get_time can be called before entering
-         * virtual mode.
-         */
-        efi.get_time = phys_efi_get_time;
         early_iounmap(runtime, sizeof(efi_runtime_services_32_t));
 
         return 0;
@@ -623,16 +601,9 @@ static int __init efi_runtime_init64(void)
          * EFI runtime services before set_virtual_address_map
          * is invoked.
          */
-        efi_phys.get_time = (efi_get_time_t *)
-                        (unsigned long)runtime->get_time;
         efi_phys.set_virtual_address_map =
                         (efi_set_virtual_address_map_t *)
                         (unsigned long)runtime->set_virtual_address_map;
-        /*
-         * Make efi_get_time can be called before entering
-         * virtual mode.
-         */
-        efi.get_time = phys_efi_get_time;
         early_iounmap(runtime, sizeof(efi_runtime_services_64_t));
 
         return 0;